Marco Saves The Day
by redantc
Summary: Marco now without Star, has decided to attend Kuoh Academy. It's time for Marco to step up and be the hero of his own story. From deuteragonist to protagonist, Marco's here to save the day. Caution: I make no promises of Marco saving anything.
1. Introduction

**Star vs. The Forces of Evil/ High School DxD**

 **Summary**

 **Marco Diaz, about two years after Star has returned to Mewni, decides to attend school in Japan, specifically Kuoh Academy. There, Marco will get into many adventures with the High School DxD cast.**

 **Planned Points in the Story**

 **Bring about some point in the story where Star will return and meet the cast,** _ **most likely on Marco's birthday**_

 **Marco will not change species, nor have any Sacred Gear**

 **Bring about the return of the Monster Arm,** _ **this will be explained in greater detail in the character analysis.**_

 **Marco will enter the story around the point of the church fight,** _ **I am not completely decided on this point.**_

 **Character- Marco**

 **Marco will be 15-16.**

 **Marco will be living alone,** _ **I will do my best not to explain this.**_

 **Marco does not have regular contact with Star.**

 **Abilities**

 **Marco will have his fighting abilities from the show,** _ **they alone will not be enough to take on the characters from High School DxD**_

 **Marco will be able to speak Japanese,** _ **to make things easier**_ **.**

 **Marco will have the ability to use, extremely weak, Mewnian magic.** _ **It will only be spells that Marco has seen Star use, at a greatly reduced efficiency.**_

 **Marco will experience a return of the Monster Arm.**

 **Spells**

 **Rainbow Avalanche**

 **Syrup Tsunami Shockwave**

 **Emerald Snake Strike**

 **Mending Heart Hurricane**

 **Mystic Room Suck Transform**

 **Radiant Shadow Transform**

 **Returnio Armius Normalrino**

 **Sparkle Glitter Bomb Expand**

 **Cotton Candy Fire Extinguish**

 **Fantastic Exit Beam**

 **Jellybean Hallucination Mist**

 **Lightning Change Back**

 **Paper Tornado**

 **Rainbow Fist Punch**

 **Rainbow Flytrap**

 **Glitter Dragon Escalation**

 **Monster Arm**

 **I intend to have the Monster Arm to be an unconscious fail safe for Marco. The Monster Arm will no longer be isolated to only Marco's right arm and it will be able to be expressed in different ways. The Arm will also no longer be sentient, although a mouth will still appear, somewhere, on his body when it is being used and it will still be a dark influence. Marco will also gain a complete squid-monster transformation later in the story, think of the arm possessing his body.**

 **Problems**

 **I am not a High School DxD fan and lack knowledge on the subject matter. There is also the fact that I will likely abandon the story soon after I start.**


	2. Chapter 1

**Marco Saves The Day Chapter 1**

Marco sits in the middle of his small living room floor, deep in concentration, a heart glowing weakly on his forehead. Tomorrow was going to be his first day of school at Kuoh Academy, but he had something to attend to first.

"Sparkle Glitter Bomb Expand," Marco yells suddenly. The room is briefly covered in an explosion of glitter.

Marco waits excitedly for the glitter to clear from his vision. A moment passes. Then another. Then another.

"I'm BLIND." Marco, blinded, runs into a nearby wall. Knocking himself out.

Marco wakes up in the morning. Looking around his, now glitter covered apartment he sighs. The spell was meant to expand the size of his living room, but had instead just created a huge mess. Marco had been practicing these spells for two years now and this was the best he could accomplish. Where Star had almost doubled the size of his house in a matter of moments, Marco couldn't even add so much as a closet after nearly an hour of intense focus.

'Oh well,' Marco thinks, discouraged. Marco looks at his clock and realizes that school would be starting shortly. Marco gets dressed quickly, putting the Kuoh uniform over his red hoodie, and runs to school.

 **Kuoh Academy**

Marco thought that he would stand out at Kuoh Academy, what with him being a foreigner, but as he looked around the halls of Kuoh he found that this was not the case. There were people of all types wearing the school uniform. Apparently Kuoh was some form of beacon for all of the foreign students in Japan. In this crowd of redheads, blonds, and brunets; he appeared almost plain.

As Marco nears his classroom, he hears soft giggling coming from his side. There are three boys, from what Marco believed to be sophomore year, crouched around what appeared to be a magazine in front of the adjacent classroom. Marco noticed that the other students were ignoring the boys and giving them a fair margin as they walked. Deciding to get a closer look Marco approached the boys only to find that they were dealing with something of a perverted nature. Marco resolved to avoid the boys from that point on. He didn't want to develop the type of reputation that hanging around those boys would bring.

The school day passed without incident, honestly the only thing that really stuck was the girl that sat next to him during class. Koneko and that was only due to her name and appears resembling a cat. Oh well, he didn't really expect this school to be any different from the old one.

Getting home Marco now had to clean his apartment, deciding to kill two birds with one stone, Marco sits down and concentrates. Marco breaks out into a sweat as a glowing heart appears on his forehead.

"Mystic Room Suck Transformation," A small hole appears in the center of his new home. Lazily, the glitter begins to move toward the, newly formed, black hole. It takes a while but eventually all of the glitter is gone.

Satisfied, Marco begins to study the future course work. He likes to be prepared, they don't call him safe boy for nothing.

A few hours into his studying Marco's right arm began to grow numb. He glares at it for a long moment. This was the arm that was once the Monster Arm. It had promised that it would return one day, and it had indeed held true to its promise. Although weak, Marco could still feel the Monster Arm's presence within him just waiting to get out.

"Returnio Armius Narmalrino," although Marco knew that the Monster Arm was now, indeed had been for a long time, a part of him. Still it did make him feel better to occasionally make sure it didn't resurface, and it had the added benefit of removing the numbness.

Marco, tired from using so much magic, decided to go to bed. Before falling asleep, Marco briefly wondered if he should be using magic as frequently as he was. No, he decided, there were absolutely no draw backs to him using magic it's not like there was someone monitoring the area for people using magic. That would be ridiculous.

 **Elsewhere**

"I'm telling you Sona there's someone using magic near the school," yells a redheaded devil.

"Rias there is so little magic being used, it's probably just a fairy passing by," replies her blue haired friend. Silence hangs in the air for a moment, as the two attempted to stare the other down.

Sighing the blue haired one eventually yields to her friend.

"Fine if this magical signature is still appearing in the area by next week we will go to find the source, happy?"

"Very"

 **I'm well aware that I am not the best writer, but ever since I saw the show Star vs. I knew that I had to write a crossover starring Marco. High School DxD happened to be the best fit for my purposes. If anyone else wants to take this story, feel free. I'm happy so long as this story gets written.**


	3. Chapter 2

**Marco Saves The Day Chapter 2**

Marco awoke the following morning feeling refreshed. It was going to be a good day…. Or not. Marco looked at the glittery mess that once was his school uniform.

'What to do now?' Marco wondered. While still having a fair margin of time, he would not be able to clean his uniform before school started.

Marco was left with a tough decision; either he would attend school looking like some form of failed arts and crafts project, or he would have to do **that**.

In his time with Star, Marco had learned a single disguise spell, Radiant Shadow Transform. Marco had found that his usage of the spell suffered from a major drawback: if he push as much magic into the spell as he could, it had a fifty/fifty chance of either leaving naked, or in a dress.

The chance of it leaving him naked, made sense to Marco. The spell essentially made him a new outfit, and if it didn't have the required power he would get no new clothes. The dress, however, confused Marco how would putting not enough power into the spell leave him with more than he started with. Perhaps it was because he was basing his usage of the spell on how he saw Star use it. She had provided him with a dress to sneak into St. Olga's Reform School for Wayward Princesses, and that was how he subconsciously thought how the spell was supposed to be used: making dresses.

Marco pondered his conundrum: one was embarrassing, the other had the chance of running his high school career. Marco looked at the clock, he had been thinking too long, he was running out of time. He had to make his choice.

Marco closed his eyes, a heart began to glow weakly on his forehead.

 **Five Minutes Later**

Marco opened his eyes, the heart on his forehead was only slightly brighter than before, and it would take too long him to gather the magic necessary for the spell. He needed to use an object from his past.

Going back into room Marco opened up the top shelf of his cabinet, quickly shifting through his underwear, Marco found what he was looking for. A small crystal heart with a gold port: Star's old charger.

The charger wouldn't provide Marco with more magic, but it would help him bring forth what little he had. The downside being that it would both shock him and burn him from the inside. Still though, teenagers could be far crueler than any charger.

Bracing himself, Marco put the crystal heart into his mouth. First a jolt ran through his body, Marco yelled as he was shocked. Then nothing?

'I guess, it does the burning thing the first time?' Marco thought none too sure.

Marco then returned to the living, still tentative over the thought of being randomly burned. Gathering his courage Marco uses the spell, "Radiant Shadow Transform!"

There was a poof, then the burning came, Marco ran around his apartment flailing. It was like his entire body was on fire! Marco spat out the charger, falling face first onto the ground.

"Never doing that again," Marco moaned to himself. Marco stayed on the ground for a few minutes before deciding to get up, and see what kind of mess he was at the moment.

On the bright side his got the uniform right, on the downside his hair was a mess, a faint heart was burned into his forehead, and his left arm was tingling. Marco looked into himself, yep he was also all out of a magic.

"Well there's nothing I can do about the heart right now, but at least it's not that noticeable." Marco quickly fixed his hair and left for school.

 **Kuoh Academy- Occult Club**

"Rias why did you call us here, classes are about to start?" A blond haired student asks, with Koneko silently nodding in agreement.

"Someone has been using magic in the area, and given its usage this morning, and it's proximity to the school, I'm almost convinced that it's someone that attends Kuoh Academy. I want all of you to keep an eye out for anything strange among the student body. At the moment I'm not quite sure what is using the magic, it may be a stray devil, fall angel or an exorcist pretending to be a student, and given the possible danger to the general populace of the city. We have a responsibility to find this person." Rias states, before allowing her pieces to return to their normal classes.

 **With Marco**

Marco's walk to class was much the same as it was the previous day, sans the fact that the second year was now yelling about how he got a date.

Marco's thoughts on the matter was somewhere between: that was fast and how was it possible that he got a date given his apparent perverted nature. Although asking these questions would involve actually interacting with the boy, which left a bad taste in Marco's mouth.

Classes was also pretty normal that day, except for the fact that the girl sitting next to him, Koneko, spent the first half of the day sniffing the air and the second glaring at him. During lunch he had attempted to ask the girl if she wanted part of his lunch, but she had _hissed_ at him.

Yep all in all the day was pretty okay.

 **Kuoh Academy-Occult Club**

"Sex Demon," spoke Koneko

"Wait what are talking about Koneko?" asks Rias, extremely confused at Koneko's, seemingly random, declaration.

"Diaz" added Koneko

Rias began to put the puzzle together, "Okay so you think that Marco Diaz is some form of incubus?"

Koneko shakes her head no, "Squid"

"Okay you think that Marco Diaz is some form of squid monster, but why did you call him a Sex Demon?" questioned Rias.

Koneko thinks for a moment before contributing, "Tentacles"

"After this we have to have a long discussion on what is, and isn't, considered a Sex Demon, but first why do you think that Marco Diaz is a squid monster," asks Rias.

"He smells like squid, and has a heart on his forehead that wasn't there yesterday," deadpans Koneko.

"There a lot of problems with that theory," states the blond-haired second year.

"Yeah like why would a squid monster be here on land, away from water? How would a squid monster disguise themselves, and what do squids have to do with hearts?" asks a black-haired third year.

Koneko begins to speak, but is cut off by Rias, "They're right Koneko, it's not Marco. It's Yuuma Amano. I've been following her all day and she is definitely not human, also there's the fact that I checked and she's not a student here. So the magic is almost one hundred percent her."

Koneko tries to speak again, but is once more cut off, by the black haired one, "Koneko, it was a dumb idea stop trying to force it."

"Yeah Koneko," adds the blond one as they all begin to leave.

'Some day they're going to regret this,' Koneko thinks to herself. Quite angry over the interaction.

 **Ha HAA. I'm surprised that I actually added another chapter, as I am extremely flaky.**


End file.
